OldNBold51
Petty Officer 2nd Class
- Joined
- Apr 19, 2010
- Messages
- 169
Guys, here are my symptoms:
Boat is a 95 wellcraft 232 with 7.4L carbed engine with thunderbolt ignition serial # OF437981. Over the last 6 hrs of run time, spread over 3 outings it began to have intermittent firing problems, now it's full time. Initially after a 10 minute warmup/idle cruising the boat began to misfire badly then died, not backfiring but misfiring. A quick restart and normal run for a few seconds then repeat the misfire and die. After several starts with me allowing a longer and longer rest in between starts the misfire symptoms cleared up( I also opened the hatch and just jiggled wires looking for any loose ones etc) and ran the rest of the evening without problems/symptoms. In an effort to rule out water in the gas I changed my fuel separator and added STABIL ethanol boat treatment but I didn't specifically check for water in the gas. Next outing (1 week later) the boat starts fine but i can hear spark arcing, although the idle is fine and and while inspecting I see no arc, just hear it (broad daylight). This is a fast spark arc, not a slow one like you'd hear from a single grounded plug wire. The arcing noise goes away after a few minutes, the boat runs great for 10 minutes and then repeats the symptoms stated above and I finish the night without incident. Last night was different. The boat started fine but had the spark arc noise but as always that went away. After a 5 minute cruise at slow idle the above symptoms turned up but never went away. I limped in as the boat would start and I could get about 5-10 seconds of normal run then misfire/die. Restart 5 seconds/die. fortunately I was smart enough never to get far from the dock.
Another symptom possibly unrelated: Prior to this problem, my alternator gauge started showing weird numbers. Upon startup, it took the alternator (according to the gauge) a minute or 2 to show that it was charging over 12V's. The gauge reads 12.5-13.5V's at idle up to about 1200 r's then the reading falls off to about 12V or less when cruising at 2K rpm's. I have not put a multimeter on the alternator to check actual voltage.
Guys, what steps do i need to do to isolate my problem and in what order?
Boat is a 95 wellcraft 232 with 7.4L carbed engine with thunderbolt ignition serial # OF437981. Over the last 6 hrs of run time, spread over 3 outings it began to have intermittent firing problems, now it's full time. Initially after a 10 minute warmup/idle cruising the boat began to misfire badly then died, not backfiring but misfiring. A quick restart and normal run for a few seconds then repeat the misfire and die. After several starts with me allowing a longer and longer rest in between starts the misfire symptoms cleared up( I also opened the hatch and just jiggled wires looking for any loose ones etc) and ran the rest of the evening without problems/symptoms. In an effort to rule out water in the gas I changed my fuel separator and added STABIL ethanol boat treatment but I didn't specifically check for water in the gas. Next outing (1 week later) the boat starts fine but i can hear spark arcing, although the idle is fine and and while inspecting I see no arc, just hear it (broad daylight). This is a fast spark arc, not a slow one like you'd hear from a single grounded plug wire. The arcing noise goes away after a few minutes, the boat runs great for 10 minutes and then repeats the symptoms stated above and I finish the night without incident. Last night was different. The boat started fine but had the spark arc noise but as always that went away. After a 5 minute cruise at slow idle the above symptoms turned up but never went away. I limped in as the boat would start and I could get about 5-10 seconds of normal run then misfire/die. Restart 5 seconds/die. fortunately I was smart enough never to get far from the dock.
Another symptom possibly unrelated: Prior to this problem, my alternator gauge started showing weird numbers. Upon startup, it took the alternator (according to the gauge) a minute or 2 to show that it was charging over 12V's. The gauge reads 12.5-13.5V's at idle up to about 1200 r's then the reading falls off to about 12V or less when cruising at 2K rpm's. I have not put a multimeter on the alternator to check actual voltage.
Guys, what steps do i need to do to isolate my problem and in what order?
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